The present invention pertains to microwave heating utensils, processes of making such utensils and decals useful in the manufacture of such utensils.
In typical microwave heating processes such as microwave cooking, microwave radiation is absorbed and converted to heat by the article to be heated. Thus, in ordinary microwave cooking microwave energy is absorbed by the food itself so that heat is generated within the food. In certain microwave heating processes, however, it is also desirable to apply externally generated heat as well. For example, meat cooked solely by internal absorption of microwave energy does not develop the desirable seared or browned exterior formed in conventional cooking processes. In cooking meat by microwave radiation, it is accordingly desirable to apply externally generated heat to the surface of the meat so as to sear or brown the meat.
Utensils incorporating microwave absorbent materials have been made and utilized in the past for such applications. The microwave-absorbent material absorbs microwave energy and converts it into heat, thus heating the utensil. Accordingly, food placed in such a utensil and exposed to microwave energy is heated both by absorption of microwave radiation within the food and by heat transfer from the hot utensil to the food. Such utensils permit cooking and browning of meat in a typical microwave oven.
One microwave heating utensil commercially available heretofore has included a glass-ceramic body substantially transparent to microwave radiation and a continuous microwave absorbent tin-laden layer on a surface of the body. The tin-laden layer typically is formed by contacting the glass-ceramic with stannous chloride vapors. Despite the extensive efforts devoted to development of microwave heating utensils and utensil-making processes heretofore, there have still been needs for further improvement. There have been particular needs for more economical utensil-making processes and for utensils which can be fabricated by such processes.